I maintain that the biggest audience for books these days isn't necessarily readers, but aspiring writers. What if Random House turned itself into a tourist attraction -- say, charge $75 per person for a tour once per week. Junior editorial assistant or interns could lead the tours, which would end with a ten minute Q&A with someone from marketing, publicity or editorial (again on a rotating schedule). You could rotate the tour among various imprints, so it's not too disruptive.
Could Publishers Start Charging For Office Tours?